1. Technical Field
The present invention relates to a multi-coaxial cable assembly and a manufacturing method of the same, and further specifically relates to the multi-coaxial cable assembly capable of improving a connection structure/method between a plurality of coaxial cables of a multi-coaxial cable, and a wiring pattern of a wiring board or a connector.
2. Description of Related Art
As illustrated in FIG. 12, a conventional connection method of an superfine coaxial cable (superfine coaxial line) used in a medical device and an electronic device includes the steps of: stripping stepwise sequentially jackets 105, external conductors (shield lines) 104, and insulators 103 of a terminal of a plurality of superfine coaxial cables 101, and exposing the external conductors 104, the insulators 103, and center conductors 102 respectively, then parallely arranging these exposed plurality of coaxial cables 101, then connecting the exposed external conductors 104 to ground lines 107 of a printed board or a connector by using solder 108, etc, and connecting the exposed center conductors 102 to signal lines (electrode pad for signal lines) 106 of the printed board or the connector by solder 108, etc.
The above-described connection structure/form is formed, for example, by a manufacturing method as described below.
First, the coaxial cables 101, with length up to terminals made uniform, are parallely arranged on a jig in which parallel grooves are formed, and by using resin and adhesive agent, etc, the coaxial cables 101 are fixed to each other so as to be maintained in a parallely arranged state, and set in a flat cable state.
The jackets 105 of the coaxial cables 101 are collectively notched by, for example, laser beam and a cutter in a direction orthogonal to an axial direction, then the jackets 105 are collectively pulled-off from the terminal side of the coaxial cables 101, and the external conductors 104 are thereby exposed.
Next, the exposed external conductors 104 are cut by the laser beam and the cutter, while leaving a required length for connection, and the insulators 103 are thereby exposed.
The exposed insulators 103 are collectively notched and pulled off again by using the laser beam and the cutter, while leaving a length that allows no short circuit to occur between the external conductors 104 and the center conductors 102, when the coaxial cables 101 are connected to the printed board or the connector, and thereby the center conductors 102 are exposed.
By using the above-described method, the plurality of coaxial cables 101, with the external conductors 104, the insulators 103, and the center conductors 102 exposed and arranged in the terminals, are positioned so as to be preferably connected to the ground lines 107 and the signal lines 106 of the printed board or the connector, and by using the solder 108, etc, the external conductors 104 are connected to the ground lines 107, and the center conductors 102 are connected to the signal lines 106, electrically, collectively, or individually.
However, in the aforementioned conventional connection method of the superfine coaxial cables, strip work must be performed twice, to expose the external conductors 104 and the center conductors 102.
In addition, exposed parts of the external conductors 104 and exposed parts of the center conductors 102 are distributed in a wiring direction (axial direction) of the coaxial cables 101, and the plurality of coaxial cables 101 are parallely arranged and also distributed in a parallel direction orthogonal to the wiring direction. Therefore, when the coaxial cables 101 are connected to the printed board or the connector, positioning accuracy is required in two directions such as the wiring direction and the parallel direction, and further a certain degree of area is required in a wiring pattern such as the ground lines 107 and the signal lines 106 provided in the printed board and the connector.
Moreover, in recent years, further superfine coaxial cables have been progressed, and it is difficult to maintain a parallel state capable of performing a sufficient positioning of the external conductors, the insulators, the center conductors of the plurality of coaxial cables in a state of exposing terminal connection parts, with respect to the wiring patterns of the printed board or the connector.
Therefore, in order to maintain the parallel state of the plurality of coaxial cables, for example, patent document 1 (Japanese Patent Laid Open Publication No. 2003-141951) proposes a method of parallely arranging a plurality of coaxial cables with external conductors exposed; fixing two ground bars extending in a parallel direction of the coaxial cables to the external conductors with two ground bars extending in the parallel direction exposed, and maintaining a parallel state of the center conductors and the external conductors by the ground bars, until the center conductor between two ground bars is exposed.
Also, for example, patent document 2 (Japanese Patent Laid Open Publication No. 2003-123882) proposes a method of collectively cutting the end parts of the coaxial cables arranged in parallel, without sequentially peeling off and exposing the external conductors and the center conductors of the superfine coaxial cables, and collectively connecting the center conductors and the external conductors of a sectional face in a non-peeling off state, directly to the wiring pattern of the printed board.
However, in the method of the aforementioned patent document 1, the terminals of the coaxial cables can be maintained in parallel state by using the two ground bars. However, wider area of the wiring pattern for connecting to the printed board or the connector is required, and the accuracy required for positioning is not different from the related art shown in FIG. 12.
Further, in the method of patent document 2, the strip work performed twice can be shortened to a cutting work of once, and this cutting work provides a cut section in which the external conductors are concentrically arranged around the center conductors of the superfine coaxial cables, and the wiring pattern at the printed board side, to which the coaxial cables are connected, is the wiring pattern fitted to the concentric arrangement in the aforementioned cut section. Therefore, there is a problem that accuracy more than that of the related art shown in FIG. 12 is required for positioning at the time of connection.